Electric circuit controller



Fell 8, 1955 w. R. GRACEY, JR

ELECTRIC CIRCUIT CONTROLLER Original Filed Dec. 28, 1948 3 Shets-Shee'c 1 IN V EN TOR.

w k, HIS TYURNEY Feb. 8, 1955 w. R. GRACEY, JR

ELECTRIC CIRCUIT CONTROLLER Original Filed Dec. 28, 1948 3 Sheets-Sheet 2 Wb'llmz H. @Pacey Jr? H65' TTOHZYEY Feb 8, 1955 w. R. GRACEY, JR

ELECTRIC CIRCUIT CONTROLLER Original Filed D60. 28, 1948 3 Sheets-Sheet 3 w si w @Q L@ @I INVENTCR. IVz'llz'am I?. 01110051 Jr. BY

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United States Patent() ELECTRIC CIRCUIT CONTROLLER William R. Gracey, Jr., Alexandria, Va., assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Original application December 27, 1948, Serial No.

. 67,264, now Patent No. 2,651,698, dated September 8, 1953. Divided and this application July 16, 1952, Serial No. 299,270

6 Claims. (Cl. 200--5) My invention relates to an electric circuit controller, and particularly to a controller for shunting a track circuit and for controlling other circuits in a railway signal or control system.

The present application is a division of my copending application, Serial No. 67,264, filed on December 27, 1948, now U. S. Patent 2,651,698 granted September 8, 1953, for Electric Circuit Controllers.

It is sometimes necessary or convenient to provide a manually operable track switch in a section of a railway in which the signals are automatically controlled. In order to protect trains approaching such a switch, it is desirable to prevent manual operation of the switch until the signals have been set to stop for an adequate warning period. This may be done by providing a switch lock controlled by a manually movable member and a timer. The manual member may be operated at any time to set the signals governing the track approaching the switch to display a stop aspect, and start the timing mechanism running. After a predetermined time has expired, the timing mechanism releases the lock to permit manual actuation of the track switch.

The Letters Patent of the United States No. 2,539,937 issued to Howard A. Thompson, on January 30, 1951, for Traflic Protection Apparatus, illustrates a switch locking system of this type. Thompson shows a track switch operable by means of an electrically locked hand-throw lever, and a circuit controller operated by an auxiliary lever movable between normal and reverse positions. When this auxiliary lever is rst moved away from its normal position, the circuit controller shunts the track circuit, thereby setting the signals governing trains approaching the switch t stop. As the motion of the manual auxiliarylever to its reverse position is completed, it actuates additionalA contacts to initiate the operation of a timing mechanism which eventually releases the electric lock on the hand-throw lever of the track switch.

' The present invention relates to a circuit controller for use in a system of the type described in the Thompson atent.

p"An electric circuit controller for shunting a railway track circuit and for controlling additional circuits, if mounted on the railway ties, is subject to severe conditions of vibration. This vibration will cause undue wear between the parts if relative motion of the parts is not prevented.

Where such a controller is used to shunt a track circuit on an electric railway, it must have high current carrying capacity. On electrified railways, the rails are commonly used as a current ow path, and unbalanced resistance conditions in the opposite rails may cause high current ow through track shunting contacts. Such a controller must therefore have heavy duty contacts. If the controller is required to additionally control other circuits, for example, signal or control circuits, then additional light duty contacts must be provided in the controller.

Where a controller is to be mounted on the ties of a railway, it is desirable that its overall height be low enough so that it may be mounted between the rails of a track without projecting suthciently above the track to foul any portion of the equipment passing over it. t

An object of my invention is therefore to provide an improved electric circuit controller of high current carrying capacity.

. Another object is to provide an electrical circuit conice troller which may be subjected to severe vibration without producing undue wear between the moving parts of the controller.

A further object is to provide an improved controller including a set of heavy duty contacts and a set of light duty contacts in the same casing and operated by movement of the same control member.

A further object is to provide an improved controller of the type described in a compact structure so arranged that it may be mounted between the rails of a railway track without projecting far enough above the track rails to foul rolling stock passing over it.

According to my invention, I achieve these objects by using elongated fixed and movable contacts mounted horizontally, and support the movable contact so that it is moved horizontally to open and close the circuit. This construction aids in keeping the overall height of my controller at a minimum. In order to provide high current carrying capacity, one of the contacts is made in the form of a ilat bar having convex upper and lower surfaces. This bar moves between a pair of ilat spring contacts which, in their disengaged condition, are spaced apart by a distance somewhat less than the distance between the opposite convex surfaces on the bar contacts. In this way, a line contact is maintained between the bar and the at springs.

The controller is operated by an external manual lever which rotates a shaft through an angle of This shaft is connected to the movable contact supporting structure through a crank and pitman to provide a linear nliloement of the `movable contact upon rotation of the s a t.

The movable contact is loosely mounted on its support so that minor misalignments between the fixed and movable contacts may be accommodated. The spring contact structure is effective when the contacts are closed to take up all lost motion in the contact supporting operating mechanism, so as to prevent wear in the operating parts due to vibration. A stationarily supported spring is provided in the path of movement of the movable contacts so as to engage those contacts as soon as they sepa-l rate from the stationary contact. This spring device places the movable contact and the contact operating element under tension, and thereby is effective when the contacts are open to take up all lost motion in either the loose mounting of the movable contact or in the bearings of the shaft, crank, and pitman.

The light duty contact assembly is mounted on a bridge structure above the pitman and is operated by a cam adjustably fixed on the crank shaft.

Other objects and advantages of my invention will be come apparent as the description proceeds.

I shall describe two forms of circuit controllers ernbodying my invention, and shall then point out the novel features thereof in claims.

In the drawings,

Fig. l is a plan view of one form of electric circuit controller constructed in accordance with my invention, with the cover removed.

Fig. 2 is a cross-sectional view of the controller taken along the line II-II of Fig. 1.

Fig. 3 is a plan view of a modified form of controller built in accordance with my invention, with the cover removed.

Fig. 4 is a cross-sectional view of the controller taken along the line IV-IV of Fig. 3, while Fig. 5 is a detail cross-sectional view taken along the line V-V of Fig. 3.

Referring to the drawings, there is shown in Figs. l and 2 a controller generally indicated at 1. The controller 1 includes a casing 2 having mounting feet 3 and a removable cover 4. A latch 5, of known construction, is provided to hold the cover in place. A squared shaft 6 projects outside the casing and carries an operating lever 7 having a handle 8.

One end of the casing 4 is open, and is closed by means of an insulating plate 9 attached to the casing by means of bolts 10. Four contact supporting blocks are secured to the insulating plate 9, in spaced pairs, only three of the blocks 11, 12 and 13 being illustrated in the drawings. The blocks are secured to the plate 9 by means of bolts 15, the blocks carrying the electrical terminals 16, 17 and 18, respectively, and the terminal 19 for the block not illustrated. The electrical terminals extend outwardly through the insulating plate 9. The outside ends of these terminals are adapted for the attachment of suitable heavy current conductors for shunting the rails of a track circuit. Inside the casing 4, each of the contact s upporting blocks carries a pair of spaced spring contact blades 20. These blades 20 are elongated in the horizontal plane and are slotted, as at 20a, to permit independent movement of the portions between the slots, so as to accommodate misalignment of the contacts.

It should be noted that the blades 20 on the upper contact supporting blocks 11 and 12 are horizontally aligned with each other and that the blades 20 on the lower contact supporting blocks are likewise horizontally aligned with each other. The upper set of blades 20 is adapted tol be bridged by a movable contact bar 21, and the lower lse't ozfzblades 20 may be bridged by a movable Contact The bars 21 and 22 are formed with relatively narrow edge portions 21a, 2lb, 22a, and 22b and wider central portions 21C and 22C lhaving convex surfaces. The conve'x surfaces 21e` and 22C are made wider than the distance between the lspring blades 20, so that when the contact bars 21 and 22 move between the blades 20, those blades ride on the convex surfaces, thereby producing substantially a line contact between the blades and the contact bars.

The advantage of a, line contact is that it provides high current carrying capacity while the force necessary to operate themovable contacts is held at a minimum. This advantage is gained by arranging the parts to produce high contact pressures so that correspondingly high current densities may be used.

A line vContact could alternatively be obtained through the use of a flat bar contact and a contoured spring contact. The construction shown is greatly to be preferred, however, since it is much easier to maintain accurate dimensions in a solid bar with `a convex contour than it is ina relatively thin ilexible spring with a corresponding contour. The dimensions of the bar'and spring contacts are very important in this construction, because these dimensions are major factors in determining the contact pressure and hence the allowable current density.

The opposite "ends of the contact bars 21 and 22 are loosely received in recesses 23 formed in a pair of movable contact supporting slide blocks 24, of `insulating material. Each of the slide blocks 24 moves between a lower guiding vsurface 25 formed in the casing 2 and van upper guiding surface 26 formed on the lower side of a rail 27 attached to the side of casing 2 by means of bolts 2 8.l

The slide-blocks 24 are connected by means of a crosshead rod 29, which is inturn connected by two pitmans 30 to crank arms 31 attached to the `shaft 6. Each pitman 30 is connected to its associated crank arm 31 by means of a pin 32. Eachpitman v30 is curved, as indicated at 30a in Fig. 2 to permit rotation of the shaft 6 further in a counterclockwise direction (as viewed in Fig. 2,)y vthan would otherwise be possible.k The crank arms 31 are rigidly attached to the shaft 6 by any suitable'means, as for example by using a'split crank arm as indicated at 31a, and a bolt 31b to tighten the opposite parts of the crank arm together.

At all bearings, such as the bearingsof shaft 6, vthe `pins 32, andthe crosshead rod 29, a certain small clearance must beallowed so that the relatively rotatable members can turn freely andrwithout binding. A controller intended to be mounted on a railway track is likely to be subjected to very severe conditions of vibration. The vibration tends to cause the relatively rotatable parts to move relative to each other, because of the clearances between them, thereby causing friction and wear of the parts. Also, the vibration might cause lmovement and wear of the contact bars 21 and 22 in their sockets 23 unless some means is provided to prevent it.

I prevent wear due to such vibration conditions by the provision of two springs 33 mounted on a bracket 34 so that they are aligned with the contact bars 21 and 22. The bracket 34 is attached as by bolts 35 to the bottom of the casing 4. The springs 33 vare so arranged that'as the contact bars 21 and22 move to their normal open circuit position, as shown in the drawings, they'engage the springs 33. `The springs 33 thereby hold the contact bars 21 and 22 tightly against the left-hand ends ofther supporting 4 recesses 23, as viewed in Fig. 2. At the same time, the springs 33 place all the bearings associated with the pitman 30, crank 31, and shaft 6 under tension, so that all lost motion due to clearances between these parts is taken up. Since the parts are held rmly against each other, they cannot rub or pound so as to cause excessive wear.

The stationary contact assembly, including the mounting plate 9, the contact supporting blocks 11, 12, and 13, the connectors 16, 17, 18, and 19, and the contact blades 19 is removable as a unit from the casing by taking out the attaching bolts 10.

The light duty contacts of my controller are mounted on a pair of supports 36 which are removably attached to the bottom of the casing adjacent the opposite sides thereof. An insulating plate 37 is attached to the tops of the supports 36, and bridges the pitmans 30. The plate 37 carries a row of fixed contacts 38, and a row of movable contacts 39, all of the leaf spring type. The movable contacts 39 are longer than the xed contacts 38, and their ends project into suitable notches 40 vformed in an insulating member 41. The member 41 is carried by a yoke 42, whose ends are pivotally attached to a shaft 43 journaled in the supports 36.

The insulating member 41 is carried on a crossbar 42a of yoke 42. `At the ends of the crossbar 42a the yoke is provided with bolts 44 which engage hubs 45 `formed in the casing 2, in which hubs the shaft 6 turns. A pair of biasing springs 46 have their upper ends connected to the yoke 42 and their lower ends connected to brackets 47, which are attached to the casing 2 by certain of the bolts which hold the supports 36. The biasing springs -46 hold the yoke 42 down so that screws 44 engage the hubs 45. The insulating support 41 is then in the path of movement of an adjustable cam 48 mounted on the shaft 6. With this construction, `the entire light duty contact assembly including supports 36, plate 37, contacts 38-39, yoke 42, and springs 46 may be removed as a unit for inspection or repair without disturbing the heavy duty contacts or their operating mechanism.

Cam 48 comprises an operating portion 48a and a clamping portion 48b secured together by means of an adjusting screw 48C yand a clamping bolt 48d. The "adjusting screw 48C cooperates intermediate its ends with an annular threaded groove 49 formed in the shaft 6 in such manner that Vby first backing off the clamping bolt 48d and then rotating the adjusting screw 48e the cam can be readily rotated to any desired angular position relative to the shaft. After the desired adjustment has been made, the clamping bolt is again tightened and the cam will then be securely held in its adjusted position.

The 'lower end of insulator 41 lies in the path of the operating surface of cam 48. When cam 48 engages the insulator 41, it moves upwardly, carrying with it the movable contacts 39 into engagement with their associated stationary contacts 38.

By means of -adiustable cam 48, any desired relationship may berestablished between the angular position of shaft 6 at which the heavy duty contacts are operated and the angular position of shaft 6 at which the light duty contacts are operated. For example, where the heavy duty contacts are used to shunt a track circuit, then it is desired to have the light duty contacts set so that their circuit is not completed until the motion ofthe hand operating lever 7 to its reverse position is substantially complete. This mode of operation will be secured with the cam adjusted as shown in the drawings. With lthe cam in this position, the light duty contacts are not operated until the shoulder 48e of the cam moves around and engages the insulator 41.

The insulating block 37 is provided with suitable terminals 50 connected to each of the contacts 38 and 39. The casing is provided with conduit outlets 51 for permitting the passage `of wires leading to the terminals.

It may be seen that upon clockwise rotation of the shaft 6 by the manual lever 7, the contact bars 2l and 22 willbe moved to the left to engage their respective stationary contact blades 20. After this engagementhas been made, the cam 48 will thereafter operate the light duty contacts 38 and 39 to their closed positions.

Both the fixed `and movable heavy duty contacts are elongated horizontally `to obtain the required 4size -and current carrying capacity. Thisconstruction of`the`contacts and Ithe mounting of` the movable contacts `for horizontal lmoveme'nt allow my circuit controller `to -be yconstructed with a flow' overall height so kithat itmay be readily mounted between the rails of a railway track.

Therev is `shown -in Figs. `3---5 another form of electric circuit controller, generally indicated by the reference lcharacter 52, which vis adapted for use in an installation to be described hereinafter and which includes a modified 4form of heavy duty -contact mechanism.

The 'circuit controller 52 includes a casing 53 having fa cover S4. Near the rleft end of casing `53, as it 'appears in the drawings, a shaft S extends transversely through the 'casing and outwardly beyond both `sides of the casing.

'One one end of the shaft 55 is fixed a hand-throw lever 56 and rn'the opposite end of the shaft 55 is fixed a crank arm 7.

A :circuit controller operating shaft 58 also extends `through the casing transversely and `has one end vprojecting outside the casing and carrying a hand operating The pitmans 62 are provided with lateral curves 62a to permit rotation of the crankshaft 58 farther in a countcrclockwise direction without fouling the shaft than would otherwise be the case. The opposite ends of the pitmans 62 are -pivotally connected to a crosshead rod 63 journaledat its ends in a pair of slide blocks 64. Each vof the slide blocks 64 moves between a lower guiding surface 65 cast integrally with the casing 53 and an upper guide rail 66 bolted to the side of the casing 53.

The slide blocks 64 support the opposite ends of an insulating plate 67, which carries the movable contacts of the heavy duty circuit controller. These slide blocks 64 are provided with apertures 64a which loosely receive projections 67a on the ends of the insulating plate 67, so that the latter is loosely mounted at its ends in the slide blocks 64.

Mounted on the insulating plate 67 are two sets of heavy duty contacts, the sets being generally indicated respectively by the reference characters 68 and 69. Each set comprises two channel-shaped spring members 70 and 71 (see Fig. 4) of different widths. These channelshaped members are held together in nested relation on the insulating plate 67 by means of bolts 72. The spring members 70 and 71 are slotted, as shown at 70a in Fig. 3, so as to accommodate misalignment of the contacts.

Each set of movable heavy duty contacts 68 and 69 cooperates with a pair of upper and lower stationary contact bars 73 and 74. The contact bars 73 and 74 are mounted by means of bolts 75 on an insulating terminal board 76 which closes an open end of the casing 53. The contact bars 73 and 74 are provided with integral extensions 73a and 74a which pass through the insulating board 76 and are provided outside the casing 53 with terminal lugs 77.

The contact bars 73 and 74 are provided with relatively thin edge portions 73b and 74b narrower than the space between the spring contact members 70 and 71, and relatively thick central portions having convex surfaces 73c and 74C. These convex surfaces are made wider than the distance between the spring blades 70 and 71, so that when the blades engage the contact bars, a line contact is produced.

A spring loading mechanism is provided for the heavy duty movable contact structure to prevent rattling and wear due to vibration. This mechanism includes a U- shaped bracket 78 mounted on the bottom of the casing 53. Two spring rods 79 extend through apertures in the opposite sides of the bracket 78. Each spring rod 79 carries a spring retaining washer 80. A spring 81 encircles cach spring rod between the left side of the U-shaped bracket 78 and the spring retaining washer 80. The springs 81 bias the spring rods 79 to a position in which the washers 80 engage the inner surface of the right-hand side of the U-shaped bracket 78. When the movable heavy duty contact structure is in its normal position, as shown, the insulating plate 67 is moved against the ends of the spring rods 79 so as to compress the springs 81. The springs 81 are thereby effective to take up all lost motion between the plate 67 and the slide blocks 64, and are also effective to take up the lost motion in the bear- The light duty contact structure ofymy controlleris mounted on a. pair of supports 82 which are attached to the bottom Vof the casing 53 adjacent the opposite sides thereof by means of bolts 83. An insulating plate 84 is mounted on the supports 82, spanning Vthe pitmans 62. The plate 84 carries 'a row yof fixed contacts 85 and a row of movable contacts 86, all of the leaf springy type. The movable contacts "86 lare longer than the-fixed contacts 85, and their 'ends `project into suitable notches formed in an insulating member 87. The member 87 is 'carried by a yoke 88, whose ends are pivotally mounted on pins 89 set in the supports 82. The yoke 88 has a crossbar 88a which carries the insulating member 87. Thev lower edge of crossbar 88a is contoured to provide a cam follower which cooperates with a cam 90 attached to the shaft 58. A spring vr88b, connected between yoke 88 and a bracket 88e held in place by one of the bolts 83, biases the fol'- lower into engagement 'with cam 90. As in the case of the controller of Figs. l and 2, the entire light duty lcontact assembly may be removed for kinspection .or repair without disturbing the heavy duty contacts.

Cam 90 (see Fig. 5) comprises two portions 90a and A90b secured together on the shaft 58 by means of `a clamping bolt 91. An adjusting screw 92 passes freely through openings in the cam portions 90a and 90b and is held against longitudinal movement with respect to those cam portions by its head and by a Ilock nut 93, respectively. The adjusting screw 92 cooperates intermediate its ends with an annular threaded groove 58a formed in the shaft 58. By loosening the clamping bolt 91 and rotating the adjusting screw 92, the `cam maybe readily moved toany desired angular Aposition relative tothe shaft. Ifl the clamping bolt is again tightened, the cam will then be securely held in its adjusted position.

By adjustment of cam 90, any desired 'relationship may be established between the angular position of shaft 58 at which the heavy duty contacts close and the angular position at which the light duty contacts close.

When the circuit controller shaft 58 is operated by the lever 59 through 180 clockwise from the position shown in the drawings, then, with the cam adjustment illustrated, the heavy duty contacts will close first, and the light duty contacts will close later when the shoulder 90C of cam 90 engages the cam follower 88a.

Although I have herein shown and described only two forms of circuit controllers embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. An electric circuit controller comprising fixed and movable heavy duty contacts at least one of said contacts including a heavy spring which is deflected upon engagement of said contacts, rfixed and movable light duty contacts at least one of said contacts including a light spring which is deflected upon engagement of said contacts, common operating mechanism for both the heavy duty and light duty contacts including a shaft, means for rotating the shaft, a crank on the shaft, a pitman connecting the crank to the movable heavy duty contacts, a cam on the shaft, and a follower for the cam connected to the movable light duty contacts.

2. An electric circuit controller as in claim l, including a support for said light duty contacts, means on the support for mounting said cam follower, a spring connecting the support and the follower and biasing the follower into engagement with the cam, a casing for enclosing all the contacts and their operating mechanism, and means for removably attaching the support to the casing so that the support, light duty contacts, spring and follower may be removed therefrom without disturbing the heavy duty contacts or their operating mechanism.

3. An electric circuit controller comprising fixed and movable heavy duty contacts, fixed and movable light duty contacts, common operating mechanism for the movable heavy duty and light duty contacts including a shaft, a crank on the shaft, means for supporting the movable heavy duty contacts, means guiding said supporting means for llnear movement, a pitman connecting the crank to said supporting means, a terminal board for supporting said light duty contacts, means for mounting said terminal board spanning said pitman, a cam on the shaft, a cam follower pivoted on said mounting means and operatively ings of the mechanism which drives the slide blocks 64. connected to the movable light duty contacts, and means 7 for rotating said shaft to cause engagement and disengagement of said fixed and movable contacts.

t 4,. Anelectric circuit controller comprising fixed and movable heavy duty contacts, fixed and movable light duty contacts,A common operating mechanism for the movable heavy duty and light duty contacts including a shaft, a ycrank on the shaft, means for supporting the movable heavy duty contacts, means guiding said supporting means for linear movement, a pitman connecting the crank to said supporting means, a terminal board for supporting said light duty contacts, means for mounting said terminal board spanning said pitman, a cam on the shaft, a yoke pivoted on said mounting means and operatively connected to the movable light duty contacts, a cam follower on said yoke cooperating with said cam, and means for rotating said shaft to move said supporting means linearly and said yoke angularly to engage and disengage the heavy and light duty contacts respectively.

5. A circuit controller comprising an enclosure, an insulating member at one end, fixed heavy duty contacts secured to said insulating member, a linearly movable support within said enclosure adjacent the one end thereof, movable heavy duty contacts secured to said support and adapted to engage the fixed heavy duty contacts, a shaft journaled at the other end of said enclosure, a crank on said shaft, a pitman interconnecting said crank and the movable support, a terminal board within said enclosure and spanning said pitman, fixed and movable light duty contacts supported by said terminal board, a yoke pivoted in said enclosure between said shaft and said movable support and operatively connected with the light duty contacts, a cam on said shaft, a cam follower on said yoke cooperating with said' cam, and means for rotating said shaft to move said movable support linearly and saidyoke angularly to engage and disengage the heavy and light duty contacts respectively.

6. A circuit controller comprising an enclosure, an insulating member at one end, fixed heavy duty contacts secured to said insulating member, a linearly movable support within said enclosure adjacent the one end thereof, movable heavy duty contacts secured to said support and adapted to engage the fixed heavy duty contacts, a shaft journaled at the other end of said enclosure, a crank on said shaft, a pitman interconnecting said crank and the movable support, a terminal board within said enclosure and spanning said pitman, fixed and movable light duty contacts supported by said terminal board, a yoke pivoted in said enclosure between said shaft and said movable support, an insulating member carried by said yoke and operatively connected with the movable light duty contacts, a cam on said shaft, a cam follower on said yoke cooperating with said cam, and means for rotating said shaft to move said movable support linearly and said yoke angularly to engage and disengage the heavy and light duty contacts respectively. t

References Cited in the file of this patent UNITED STATES PATENTS 1,126,043 Livermore Jan. 26, 1915 1,887,273 Lewis Nov. 8, 1932 2,103,123 Stevens Dec. 2l, 1937 2,580,732 Cohen Jan. 1, 1952 

